Internal combustion engine



Feb. 13, 1934. R. N. DU BOIS INTERNAL COMBUSTION ENGINE Filed Nov. 15, 1929 3 Sheets-Sheet l ATTO RN EY Feb. 13, 1934. R. N. DU BOIS INTERNAL COMBUSTION ENGINE Filed Nov. 15, 1929 3 Sheets-Sheet 2 ATTO RN EY Feb. 13, 1934. R. N. DU BOIS 1,947,252

INTERNAL COMBUSTION ENGINE 7 Filed Nov. 15, 1929 s Sheets-Sheet 3 ATTORNEY.

Patented Feb. 13,. 1934 UNITED STATES PATENT, OFFICE 1,947,252 7 INTERNAL COMBUSTION ENGINE Application November 1929 Serial No. 407,322

8Claims.

My invention relates to air cooled internal combustion engines of the type which comprises a plurality of cylinders whose axes extend radially with respect to the'crank shaft axis, and is more 6 particularly'related to a manifold structure and assembly. The structure, hereinafter described, is especially adapted for use with radial aircraft engines, but I do not wish to limit the invention exclusively to such use, as the principle of my invention may be embodied in other types of air cooled internal combustion engines.

, In the design of air cooled engines, and especially in those designed for aircraft use, it is quite desirable to minimize air resistance as much as possible. The present day practice is to equip the engine with a number of various accessories, such as means for heating the gases prior to entrance into the cylinder, and for warming the air taken into the carburetor. Such devices are bulky and greatly add to the air resistance, being especially objectionablewhen they project beyond the limits of the cylinders.- Because of this fact, these accessories are soine times omitted, since the maintenance of relative low air resistance is more advantageous than the benefits derived from'the use of such accessory devices.

' An object of. my present" invention is to overcome the above mentioneddifficulties by providing a manifold assembly .of new construction wherein such accessory devicesmay be economically and advantageously incorporated therewith without materially'adding to the air resistance. A further object of my invention is to increase the efficiency of air cooled radial internal combustion engines by providing an improved manifold structure, that may be economically manufactured and assembled with the engine, and which is so compactly'arranged that it produces an improved result in engine performance as well as minimizing the air resistance.

For a more detailed understanding of the invention, reference may be had to the accompanying drawings which illustrate one form which my invention may assume, and in which:

Fig. 1 is a front elevation of a radial internal combustion engine showing my improved compact manifold assembly;

Fig. 2 is a vertical side elevational view partly in section of the manifold assembly and showing the relation of the same with the crank shaft Fig. 3 is afltransverse vertical sectional view taken substantially on the line 3--3 of Fig. 2,

. Fig.4 is a vertical transverse sectional view taken on the line 4-4 of Fig. 2 and showing the air heater associated with a portion of the exhaust manifold, and

Fig. 5 is a longitudinal sectional view of the engine and manifold assembly.

The drawings illustrate an air cooled radial in- 601 ternal combustion engine which includes a plural ity ofcylinders 10 whose axes extend radially with respect to the axis 11 of the crank shaft; The usual type of exhaust manifold is associated with this engine and comprises a hollow ring 12,- the exhaust ports of each cylinder being connected with the hollow ring by means of the tubular exhaust pipes 13. The exhaustgases are exhausted from each cylinder into the hollow ring 12 and thence exhausted through the exhaust pipe 14 that extends rearwardly in between two adjacent cylinders of the engine, preferably adjacent the bottom thereof.

' The aboveclem'ents are standard design and my invention relates particularly to an improved (5 manifold structure that may be especially connected with'the exhaust pipe 14. An intake manifold 15 is associated with the engine and preferably located at the rear thereof, the exhaust ring beingpreferably located at the front of the engine'in accordance with the usual engineering practice at the present time. The intake mani fold 15 is provided withthe jacket 16 and an inlet port' 17, the jacket 16 communicating with the'exhaust gas inlet and outlet ports 18 and 19 respectively.

Associated with the exhaust manifold is a bypass arrangement for conducting the exhaust gases through the intake manifold jacket. A pipe 20 is in open communication with the depending exhaust pipe section 14; and is connected with the intake port 18 of the jacket. A butterfly valve 21 being preferably located in the rearward extension 15 of the intake manifold for controlling the flow of exhaust gases into the jacket 16 of the said intake manifold. The exhaust pipe 14 is composed of the two sections 14' and l i which are joined together, the latter section provided with an extension 22 adapted to be connected with the outlet port 19 of the intake jacket, a butterfly valve 23 being preferably carried by the exhaust pipe section 14 and arranged to be operated in conjunction with the butterfly valve 21 so that as the valve 21 is opened to admit the gases into the intake manifold jacket, the valve 23 is closed to the flow of exhaust gases, the said exhaust gases being caused to flow around the intake manifold jacket and thence into the extension 22 from where it is permitted to flow into the exhaust manifold section tapo'sition with respect to each other.

14 and thence to the rear where the same may be exhausted into the atmosphere.

In order to provide a very compact assembly, I have provided a carburetor 25, preferably of the horizontal type which is adapted to be connected with the intake. port 1'7. The centerline of the carburetor and the intake port 1'1 are preferably coaxial and substantially equidistant from the crank shaft axis. Warm air, for mixture with the gas in the carburetor is drawn therein is in turn secured to the jacket2l' wa't encircles a portion of the exhaust manifold. section .14" to the rear of the extension .22, thus permitting. all of the exhaust gases to DQ-"S'sin proximity to the jacket 27. This jacket is preferably constructed of sheet metal and is provided with a. plurality of openings 28 through which the air for usein the carburetor is drawn, the air being circulated about the exhaust manifold section 1i and heated by the exhaust gasespr'iorto its entrance into the carburetor.

, It will be noted that theintake manifold and the exhaust manifold portion 14 are in close jux- The carburetor and heating means for heatingthe air used in the carburetor are also very close together, thus providing the very compact and simple construction that minimizes air resistance. Furthermore, the arrangement and assembly is such that all these means; that is, the exhaust manifold heater for heating the gases prior to its entrance into the cylinders, the carburetor and the means for heating the: air drawn into the carburetor, are confined withirrthe limits as defined by the extremities of the cylinder structures. The assembly as abovedescribed, is compactly associated with an engine of-thistype and various elements of the assembly are thus located onewbehind the other and closely-assembled within the limited space available for use. It will thus be seen, that I have provided a very compact manifold assembly that offers minimum resistance to the air stream and which isso compactly arranged as to-provide efilcient engine performance, thereby materially increasing the eng-ine efliciency without adding objectionable obstructions to the air stream. I

If desired, a cover 30 hinged to the elbow 26 may be raised to permit air to be directly conveyed to the carburetor without passing through the jacket 27.

In the claims and specification --I employ the term cylinder structure in its broad sense to include those cooperating parts or elements usually associated therewith, to wit, the cylinder head, rocker box and cover, my assembly being thus confined within a limit as so defined.

Although I have illustrated but one form of my invention and have described in detail but a single application thereof, it will be apparent to those skilled in the art to which my invention pertains, that various modifications and changes may be made therein without departing from the spirit of my invention or from the scope of the appended claims.

What I claim as my invention is:

1. In a manifold assembly for an air cooled internal combustion engine having a crankshaft and a plurality of cylinder structures having intake and exhaust ports and whose axes extend radially with respect to the crank shaft axis and comprising, an intake manifold provided with a gas intake port, an exhaust. collector ring connected with the cylinder exhaust port, means for conducting the exhaust gases in proximity to said intake manifold, a carburetor positioned substantially equidistant from the crankshaft axis as the inlet port of said intake manifold, the component parts of said manifold assembly compactly assembled and confined within the limits as .defined by the outer extremities of the cylinder structures to minimize air resistance.

2; In a manifold assembly for an air cooled internal combustion engine having a crankshaft through the elbow connection or coupling 26 that and a plurality of cylinder structures having in take and exhaust ports and whose axes extend radially with respect to the crankshaft axis and comprising, an intake manifold provided with a gas intake .port, an exhaust manifold structure connected with the cylinder exhaust port and provided with'a by-pass cooperating with said in take manifold to convey the exhaust gases into proximity with said intake manifold, and a horizontal carburetor, said carburetor and intake port of said intakermanifold positioned substantially equidistant from the crankshaft axis, the component parts of said manifold assembly compactly assembled and confined within the limits as defined by the outer extremities of the cylinder structures to minimize air resistance.

3. In a manifold assembly for an air cooled internal combustion engine having a crankshaft and a plurality of cylinder structures having intake and exhaust ports and whose axes extend radially with respect to the crankshaft axis and comprising, an intake manifold having an intake port and provided with a jacket, a carburetor, said carburetor and intake port of said intake manifold positioned substantially equidistant from the crankshaft axis, and an exhaust manifold structure connected with the cylinder exhaust port and provided with a by-pass in communication with the jacket of said intake manifold, the component parts of said manifold assembly compactly assembled and confined within the limits as defined by. the outer extremities of the cylinder structures to minimize air resistance.

. 4. In a manifold assembly for an air cooled internal combustion engine having a crankshaft and a plurality of cylinder structures having intake. and exhaust ports and whose axes extend radially with respect tov the crankshaft axis and comprising, an intake manifold having an intake carburetor and intake port of said intake manifold positioned substantially equidistant from the crankshaft axis, an exhaust collector ring and an exhaust manifold section connected with said collector ring and located immediately below said intake manifold and carburetor and provided with aby-pass in communication with the jacket of said intake manifold, the component parts of said manifold assembly compactly assembled and confined within the limits as defined by the outer extremities of the cylinder structures to minimize air resistance.

5. In a manifold assembly for an air cooled internal combustion engine having a crankshaft and a plurality of cylinder structures having .intake and exhaust ports and whose axes extend radially with respect to the crankshaft axis and comprising, an intake manifold having an intake port and provided with a jacket, a carburetor, said carburetor and intake port of said intake manifold positioned substantially equidistant from the crankshaft axis, an exhaust collector ring connected with the exhaust ports of said cylinders and an exhaust pipe connected with said collector ring and located immediately below said intake manifold and carburetor and'provided with a by-pass in communication with the jacketof said intake manifold, the .component parts ofsaid manifold assembly compactly assembled and confined within the limits as defined'by' the outer extremities of thecylinder structures to minimize air resistance. v I

6. In a' manifold "assembly for an air cooled internal combustion enginehaving a crankshaft and aplurality of cylinder'structures having intake and exhaust ports and whose, axes extend radially with respect to the crankshaft axis and comprising, an intakemanifold having an intake port andprovided with a jacket, a carburetor, said carburetor and intake port of said intake manifold positioned substantially equidistant from the crankshaft axis, and an exhaust collector ring connected with the exhaust portsof said cylinders and provided with an exhaust pipe located immediately below said intake manifold and carburetor and provided with a by-pass in communication with the jacket of said intake manifold, and means 'for circulating air in proximity to said exhaust pipe. and communicating-with said carburetor to supply warm air thereto, the component parts of said manifold assembly compactly assembled and confined within the limits as defined bythe outer extremities of the cylinder structures tominimi'ze air resistance.

, 7 In an air cooled internal combustionengine having a crankshaft'ancl a pluralityof cylinder structures whose axes extend radially. with respect'to the crankshaft axis, the combination therewith of an intake manifold means having a jacket, an exhaust manifold means, means for conducting the exhaust gases to the intake manifold jacket, a carburetor means, and means for conducting air into proximity with the exhaust gases to heat the same and thence into the carburetor, all of said means compactly arranged V crankshaft axis, an exhaust pipe located in juxtaposition with said carburetor and jacket carried by said intake manifold and provided with a bypass communicating with said intake manifold jacket, and an air jacket carried by said exhaust pipe and provided with air intake ports and an outlet port operatively connected with the car- I buretor, said air jacket confined within the limits as defined by the outer extremities of the cylinder structures.

RALPH N. DU 1301s. 

